Scintillators have been widely used in detecting radiation. In applications where extremely fast timing measurements are required, such as positron emission tomography (PET) imaging, neutron gauging and multiplicity, ultra fast scintillators may be desired. Materials used for the ultra fast scintillators can have a very fast luminescent-decay time of about 2 ns. However, scintillator materials that can generate a pulse length of less than 1 ns in response to a radiation strike have not been discovered. Industries keep seeking faster radiation detecting devices for the extremely fast timing measurements.